(1) The department may examine records of coal companies, including contracts for the sale of coal, to determine whether the price of coal as reported is the result of an agreement not at arm's length. The department will, if necessary, examine operator's records as they pertain to gross proceeds, make all adjustments required, and transmit the adjustments to the department's agent in the county and to the operator.

(2) The department also has the right to summon witnesses to appear and give evidence and to produce records, books, papers, and documents relating to any matter which the department shall have the authority to investigate and determine. Records obtained from the operator shall be considered confidential.